It is narrated by Ibn Abbas that he heard the Prophet saying:

The one subjected to the severest torture on the Day of Judgment shall be the one who either killed a Prophet or the one who was killed by a Prophet, or the one who has killed either of his parents and the one portraying pictures, and a scholar who does not benefit out of his knowledge.

Baihaqi

It means that the one who portrays pictures, also falls under the category of the major sins and therefore a penalty which is incurred by the murderer of a Messenger shall also be incurred by the one who portrays pictures.

It is narrated by Abu Hurairah that he heard the Prophet saying:

Allah the Almighty says that the most wrong-doer person is the one who makes an effort to create like I do. In case some one boasts of doing that, let him create a particle, a grain or a barley.

Al-Bukhari-Muslim

It implies that a portrayer (i.e. an artist) surreptitiously claims Divinity. He intends to create things which are the sole prerogative of Allah. He is the most arrogant person and a great liar.Despite the fact that he does not even possess the capability of creating a grain, he is still trying to emulate divinity. An imitator is a condemned person who is accursed by Allah.